Driver skill and responsible behavior is critical for vehicle safety. Various methods and systems have therefore been proposed for automatically monitoring a driver and the manner in which the vehicle is being driven. Such systems and methods allow objective driver evaluation to determine the quality of the driver's driving practices and facilitate the collection of qualitative and quantitative information related to the contributing causes of vehicle incidents, such as accidents. These systems and methods help to prevent or reduce vehicle accidents, and vehicle abuse, and also help to reduce vehicle operating, maintenance, and replacement costs. The social value of such devices and systems is universal, in reducing the impact of vehicle accidents. The economic value is especially significant for commercial and institutional vehicle fleets.
Driver monitoring systems vary in their features and functionality and exhibit considerable variability in their approach to the overall problem. Some focus on location and logistics, others on engine diagnostics and fuel consumption, whereas others concentrate on safety management.
For example, U.S. Pat. No. 4,500,868 to Tokitsu et al. is intended as an adjunct in driving instruction. By monitoring a variety of sensors (such as engine speed, vehicle velocity, selected transmission gear, and so forth), the system of Tokitsu determines whether certain predetermined condition thresholds are exceeded, and, if so, to signal an alarm to alert the driver. Alarms are also recorded for later review and analysis. The Tokitsu system is valuable, for example, if the driver were to rapidly depress the accelerator pedal resulting in an acceleration exceeding a predetermined threshold. This would result in an alarm, cautioning the driver to reduce the acceleration. If the driver were prone to such behavior, this is indicated in the records created by the system.
U.S. Pat. Nos. 4,671,111 and 5,570,087 to Lemelson teach the use of accelerometers and data recording/transmitting equipment to obtain and analyze vehicle acceleration and deceleration.
U.S. Pat. No. 5,270,708 to Kamishima discloses a system that detects a vehicle's position and orientation, turning, and speed, and coupled with a database of past accidents at the present location and determines whether the present vehicle's driving conditions are similar to those of a past accident, and if so, alerts the driver. If, for example, the current vehicle speed on a particular road exceeds the speed threshold previously stored in the database at that point of the road, the driver could be alerted. Moreover, if excessive speed on that particular area is known to be the cause of many accidents, the system could notify the driver of this.
U.S. Pat. No. 5,546,305 to Kondo performs an analysis of vehicle speed and acceleration, engine rotation rate, and applies threshold tests. Such an analysis can often distinguish between good driving behavior and erratic or dangerous driving behavior (via a driving “roughness” analysis). Providing a count of the number of times a driver exceeded a predetermined speed threshold, for example, may be indicative of unsafe driving.
U.S. Pat. No. 6,060,989 to Gehlot describes a system of sensors within a vehicle for determining physical impairment of the driver that might interfere with the driver's ability to safely control his vehicle. Specific physical impairments illustrated include intoxication, fatigue and drowsiness, or medicinal side-effects. In Gehlot's system, sensors monitor the driver directly, rather than the vehicle.
U.S. Pat. No. 6,438,472 to Tano, et al. describes a system which statistically analyzes driving data (such as speed and acceleration data) to obtain statistical aggregates that are used to evaluate driver performance. Unsatisfactory driver behavior is determined when certain predefined threshold values are exceeded. A driver whose behavior exceeds a statistical threshold from what is considered safe driving, is classified as a “dangerous” driver. Thresholds can be applied to the statistical measures, such as standard deviation.
In addition to the above issued patents, there are several commercially available products for monitoring vehicle driving behavior. The “Mastertrak” system by Vetronix Corporation of Santa Barbara, Calif., is intended as a fleet management system which provides an optional “safety module” that addresses vehicle speed and safety belt use. A system manufactured by SmartDriver of Houston, Tex., monitors vehicle speed, accelerator throttle position, engine and engine RPM, and can detect, count, and report on the exceeding of thresholds for these variables.